Blackboard-eraser



\N0 Model.)

W. H. SPENGE.

BLAGKBOABD ERASBR.

Patented Jam. 2, 1894.

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IINTTnn STaTns aTnNT @Trione IVILLIAM H. SPENCE, OF FAIRMOIINT, INDIANA.

BLACKBOARD-ERASER.

SPECIFICATION forming part of Letters Patent No. 511,812, dated January2, 1894.

Application filed June 26,1893.

T @ZZ wz/om it may concern:

Be it known that I, WILLIAM H. SPENCE, a citizen of the United States,residing at- Fairmount, in the countyof Grant and State of Indiana, haveinvented certain new and useful Improvements in Blackboard-Erasers; andI do herebydeclare that the following is a full, clear, and exactdescription of the same, reference being had to the annexed drawings,making a part of this specification, and to the letters of referencemarked thereon.

The present invention has relation to that class of blackboard erasersin which the erasing-pad is capable of being reversed to bring the newor unworn side of the erasing-pad in position for use when the oppositeside has become useless from wear, and consists in providing means forretaining the dust and dlrt coming from the blackboard within areceptacle at the end of the eraser-frame y and means for removing' ittherefrom, also in improving the device in the several details ofconstruction whereby a more perfect and practical device of thischaracter is provided. These objectsI attain by the constructionsubstantially as shown in the drawings and hereinafter described andclaimed.

Figure l of the drawings represents a perspective view of my improvedblackboard eraser; Fig. 2 a longitudinal vertical section thereof; Fig.3 a detail view in perspective of one end of the inclosing frame withinwhich the erasing-pad is held; Fig. l a detail View in perspective ofone end of the erasing pad.

In the accompanying drawings A represents a rectangular shapedinclosing-frame provided upon its closed side or back with finger gripsa.

A dust-guard B of felt or other suitable flexible material is connectedaround the three sides of the inclosing-frame A by means of the metalclamping-band C, which band is secured in place by the set-screws bextending through elongated slots c in said band and through thedust-guard B and into the sides of the inclosing frame. Theclamping-band through the medium of the slots and set screws may be setso as to bring the edge thereof ush with the edge of theinclosing-frame, and the dust-guard may also be adjusted or extended asit wears to bring the edge therea of on the same plane with the wearingsur- Serial No. 478,826. (No model.)

face of the eraser-pad D. This dust-guard B serves to hold thechalk-dust inside the inclosing frame A by preventing it from escapingover the sides thereof.

The erasing-pad D has two wearing surfaces as shown, consistingpreferably of felt strips, or any other suitable material may be used,which are suitably connected to the opposite faces of a block c havingat its ends grooves d. The eraser-pad D is removably held within theinclosing-case A by means of a suitable keeper e secured to the innerside of the end of the frame, which keeper engages one of the grooves c;a removable pin f engages the opposite groove and passes through holesin the sides of the frame. When it is desired to remove the eraser-padand bring into use the opposite wearing surface, the pin is withdrawnand the pad disengaged with the keeper which will allow the pad to betaken out and replaced with an unworn rubbing surface, thus enabling thesingle eraserpad with its double wearing surface to serve the wearingcapacity of two separate pads with'a single Wearing surface.

I do not wish to be understood as limiting myself to any special formofwearing surface or the means shown for holding the pad within theinclosing-frame, as any well known means may be provided for thispurpose that will enable the pad to be reversed to bring the oppositewearing surface into use when found desirable.

The inclosing-frame A may be constructed of Wood or any other suitablematerial and has its back extended to form a dust receptacle E and anopenin g g through which the accumulated chalk-dust and dirt aredischarged, said opening being closed by a pivoted slide L, or any otherwell known means may be provided for the discharge of the chalk-dust anddirt as found most preferable. Acover F is connected to the extended endof the back of the inclosing-frame by means of exible hinges z' of clothor leather, which hinges form the sides of the receptacle E by beingattached to the side edges of the extension and to the side edges of thecover. A suitable springkconnects the coverF with the back of theinclosing-frame so as to keep the cover extended as shown in full linesof Fig. 2 and thus bring the rubber or other IOC) elastic flap G inclose contact with the surface of the blackboard when the eraser isbeing used. This elastic flap G is suitably connected-to the free end ofthe cover F and is v of sufcient width to project beyond it and arms msecured in any suitable manner to' the frame so that the gate will havea yielding motion and be opened when the pin 'n comes in contacttherewith. The purpose of the gate H is to keep the space between thecover F and end of the eraser-pad D closed so as to prevent thechalk-dust and dirt from falling out should the device be turned upsidedown or carelessly thrown upon a desk.

Any suitable means may be provided that will act as a yielding gate sothat it will close and open to prevent the chalk-dust or dirt fromfalling out of the receptacle and to open the receptacle to receive thechalk-dust or dirt coming from the blackboard when the eraser is in use.

In using the eraser when brought against the surface of the blackboardto clean it, the

coverF will be forced into the position shown.

in dotted lines, Fig. 2, the pin n striking the gate H and pressing itdown as seen in dotted lines, which opens the space between the coverand end of the eraser-pad and allows the chalk-dust to pass into thereceptacle E from whence it may be removed through the opening g.

The iap or tongue G is beveled upon its edge as hereinbefore describedso as to prevent the dust and dirt from collecting and lodging thereon.

When the eraser 'is not in use or when pressure is removed from. thecover F, the spring la will force the cover back to its normal position,and pressure on the gate H being removed by the withdrawal of the pin nfrom contact therewith, the gate will close through the medium of thespring arms fm, thus preventing the chalk-dust or dirt from falling outof the receptacle should the eraser be turned upside down or carelesslyhandled.

There are many changes or modifications 5o in the details ofconstruction which may be made without departing from the principle ofmy invention which privilege I reserve as coming within the scope ot'ordinary mechanical' skill.

Having now fullyV described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. Ablackboard eraser, consisting of a suitable frame, a dust receptacleat the end thereol", an automatically operating hinged cover therefor,and a reversible eraser-pad, substantially as and for the purpose set.forth.

2. A blackboard -eraser provided with a dust receptacle,a hinged covertherefor whereby the same is rendered automatic in its ac-Y tion, and aspring connecting with the cover, substantially as and for the purposespecified.

3. A blackboard-eraser provided with a dust receptacle and a springactuated hinged cover and a spring actuated gate operating in connectiontherewith to close and open the receptacle, substantially as and for thepurpose described.

4. A blackboard-eraser consisting of asuitable inclosing-frame and asuitable flexible dust-guard adj ustably connected to the sides thereof,and a reversible eraser-pad held within the inclosing framesubstantially as and for the purpose set forth.

5. A blackboard-eraser consisting of a suitable inclosing-frame, aneraser-pad held within the same, a dust-guard connected to the sides ofthe frame, a dust receptacle upon the end of the frame, a springactuated hinged cover provided with a flexible ap or tongue, a springactuated gate operating in connection with the cover, and means forremoving the dirt from the receptacle, substantially as and for thepurpose described.

In testimony that I claim the above I have hereunto subscribed my namein the presence of two witnesses.

WILLIAM H.' SPENCE.

Witnesses:

L. R. WHITNEY,

LEVI SCOTT.

